Potential Impacts on Groundwater Resources of Geological Storage

Publication Overview

The study, comprising a literature review and desk-based assessment, aimed to produce a ‘high level’ overview of potential impacts on groundwater resources from storage operations, concentrating on DSF storage across a range of typical regional settings. The study also highlighted the current state of knowledge and/or gaps, recommending further research priorities where appropriate.

Publication Summary

Areas of geographical overlap between potential DSF CO₂ storage and overlying fresh water aquifers have been identified by combining available datasets to map the global and regional juxtaposition of groundwater resources and potential CO₂ storage sites. A classification scheme has been developed for the various geological settings in which overlap may occur. This was then tested for Europe where groundwater resources and potential CO₂ storage sites are relatively well documented and understood. In central Europe, potential storage areas coincide with areas of large, uniform potable aquifers and this could lead to potential conflicts in instances where potable aquifers extend to considerable depth, or low permeability caprock layers are scarce. In southern Europe, more complex aquifer systems (e.g. limestone karst) tend to coincide with potential storage resources. In North America it is the reversed situation, with the majority of geographical overlap occurring between complex aquifer systems and DSF and in Australia, there is overlap with deep freshwater aquifers. The situation in Australia is interesting to note as deep freshwater may coincide with potential DSF.